Transactions with Affiliates - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	2 Months Ended	3 Months Ended	7 Months Ended	9 Months Ended
	Jul. 31, 2018	Sep. 30, 2018	Sep. 30, 2019	Jul. 31, 2018	Sep. 30, 2019
Related Party Transaction [Line Items]
Service related, net		$ 259	$ 258		$ 479
Nationstar Mortgage Holdings Inc.
Related Party Transaction [Line Items]
Service related, net	$ 120			$ 901
Nationstar Mortgage Holdings Inc. | New Residential
Related Party Transaction [Line Items]
Fees paid	17			122
Revenue recognized from servicing agreements	1			3
Nationstar Mortgage Holdings Inc. | Agency MSRs | Subsidiary of New Residential | Loan Subservicing Agreement
Related Party Transaction [Line Items]
Service related, net	$ 6			$ 43